Sorry, I don't know what happened... I just pressed Enter and SDN posted my conversation too early. I wanted to add more details to the thread.
What I do is - I have a Custom Data model.
When I have only the main entity being the key, everything is working just fine.
When I make one of the main entity attributes a key field (by pressing the checkbox "key field"), I get the error in question.
I realize it's a short dump, but when I look at it, it's a short dump in the standard SAP code. When I debug the access class, everything is properly sent and I have both fields and values populated and submitted with the et_data table.
When I try to even open the UI for editing, this very same short dump happens.
Any advice?
Here is the short dump screenshot:
Cheers,
Boris